WO2009137985A1 - Method and system for inspecting special nuclear material - Google Patents

Method and system for inspecting special nuclear material Download PDF

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Publication number
WO2009137985A1
WO2009137985A1 PCT/CN2009/000498 CN2009000498W WO2009137985A1 WO 2009137985 A1 WO2009137985 A1 WO 2009137985A1 CN 2009000498 W CN2009000498 W CN 2009000498W WO 2009137985 A1 WO2009137985 A1 WO 2009137985A1
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Prior art keywords
ray
neutron
energy
electron
detected
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PCT/CN2009/000498
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French (fr)
Chinese (zh)
Inventor
康克军
杨祎罡
苗齐田
陈志强
李元景
孙尚民
彭华
杨光
刘不腐
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清华大学
同方威视技术股份有限公司
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Application filed by 清华大学, 同方威视技术股份有限公司 filed Critical 清华大学
Priority to EP09745369.0A priority Critical patent/EP2287636B1/en
Priority to US12/991,982 priority patent/US9268027B2/en
Publication of WO2009137985A1 publication Critical patent/WO2009137985A1/en
Priority to US14/047,105 priority patent/US9081099B2/en

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    • G01V5/281—
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01T—MEASUREMENT OF NUCLEAR OR X-RADIATION
    • G01T1/00—Measuring X-radiation, gamma radiation, corpuscular radiation, or cosmic radiation
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01T—MEASUREMENT OF NUCLEAR OR X-RADIATION
    • G01T3/00—Measuring neutron radiation

Definitions

  • the present invention relates to the field of dangerous goods detection, and more particularly to a method and system for detecting special nuclear materials.
  • the so-called special nuclear material refers to uranium and plutonium that can be used to make nuclear weapons. It is usually required that the uranium and plutonium contained in uranium and plutonium have an abundance of at least 93%.
  • special nuclear material testing the presence of uranium 235 and ⁇ 239 hidden in a packaged environment such as a vehicle or container is detected. Therefore, in the following, the special nuclear materials to be tested refer to uranium 235 and ⁇ 239.
  • Special nuclear materials of the order of kilograms to tens of kilograms are known to be used to construct simple nuclear bombs, posing a great threat to social security.
  • the detection limit for a particular nuclear material is defined as 100 cm 3 . This volume is very small compared to the packaging environment in which a particular nuclear material may be located, such as a container.
  • a terrorist shields or disguise a particular nuclear material the difficulty of detecting it will be further increased. Therefore, how to detect these special nuclear materials that are not "large" from the flow of goods flowing in various ports poses great challenges to the detection technology.
  • technology. ' , , , , _ ⁇ , , _ ⁇ Passive detection technology uses the spontaneous decay of special nuclear materials. When the nucleus of a particular nuclear material spontaneously decays, a prompt neutron and gamma ray signal is emitted. Special nuclear materials can be found by collecting/detecting these ray signals using detectors.
  • the intensity of the signal emitted by the special nuclear material during spontaneous decay is weak, so the passive detection result is subject to the amount of special nuclear material and its shielding, and is easily interfered by the shielding. If the probe ⁇ measures the signal count rather than the energy distribution, it cannot distinguish between the signal from the special nuclear material and the radiation background from the natural world (such as the gamma ray of potassium 40, the neutron produced by the cosmic ray), thus detecting The accuracy is very low. Moreover, passive detection techniques take longer to collect spontaneous decay signals and are not suitable for applications where higher detection speeds are required, such as airports and ports.
  • Nuclear resonance fluorescence technology is an active detection technique that utilizes electromagnetic radiation of specific energy. Shoot to illuminate special nuclear materials. When the specific energy and the nuclear energy level of a particular nuclear material are consistent, a strong absorption occurs. By measuring the absorption of specific energy electromagnetic radiation, or measuring the energy of the Y-photon emitted by an object after absorbing electromagnetic radiation, a completely deterministic detection of the presence of a particular nuclear material can be performed. This is a very accurate method.
  • nuclear resonance fluorescence technology requires the use of specialized accelerators to generate single-energy high-energy X-rays.
  • an electron accelerator of more than OOMeV and a high-power laser source are required.
  • this kind of ray source is still in the research stage and is not mature enough.
  • Another source of radiation is the direct use of the bremsstrahlung source.
  • the requirements for the electron accelerator are not high. Only electrons are required to accelerate to the MeV ⁇ l OMeV level.
  • the measurement of the nuclear resonance fluorescent photons is inevitably accompanied by a large number of Background interference, which causes a lot of interference with the measurement, is unfavorable.
  • fissile materials such as special nuclear materials (i.e., uranium 235 and thorium 239) and other nuclear materials (such as uranium 238 and thorium 240), undergo photo-fission under irradiation of radiation. Further, special nuclear materials undergo thermal neutron-induced fission under thermal neutron irradiation.
  • photo-fission can't be used to determine special nuclear materials, because they can be interfered with by other fissile materials such as uranium 238 and thorium 240.
  • the photofission process cannot distinguish between uranium 235 and uranium 238, nor can it distinguish between ⁇ 239 and ⁇ 240.
  • a method of detecting a particular nuclear material comprising:
  • Illuminating the detection area of the object with a first X-ray beam Illuminating the detection area of the object with a first X-ray beam, the energy of the X-ray beam being selected to cause observable photodisruption of a particular nuclear material that may be present in the object to be detected;
  • the detection region of the detected object is irradiated with low-energy neutrons, and the energy of the low-energy neutron is selected to cause heat of a special nuclear material which may exist in the fissile material in the object to be detected.
  • Neutron induced fission
  • an X-ray beam can be utilized to determine whether or not a fissile material is present in the object to be detected. Further, since the X-ray beam has good collimability, according to the method of the present invention, the position of the fissile material in the object to be detected can be accurately determined while determining the presence of the fissile material.
  • Subsequent thermal neutron induced fission can be performed in determining the presence of fissile material to determine if a particular nuclear material is present. Since the presence of fissile material has been determined, the use of thermal neutrons to illuminate the object for a short period of time does not significantly increase the false alarm rate. Thus, the method of the present invention can improve the detection speed and the accuracy of detection as compared to the detection of a particular nuclear material by thermal fission-induced fission.
  • the first fissile ray signal may comprise a signal.
  • the low-energy neutron may be a light neutron generated by bombarding the light neutron conversion target with the second X-ray beam, so that the same X-ray source can be used (for example, by an electron accelerator)
  • the electronic target are configured to generate the first and second X-ray beams to reduce the complexity and cost of the detection system.
  • the method further comprises detecting a suspected region of the detected object prior to the irradiating with the first X-ray beam, and using the suspected region as the detection region.
  • the special nuclear material has a high density and a high atomic number, for example, uranium and thorium have an atomic number of 92 and 94, respectively, and a density of 18.95 g/cm 3 and 19.84 g/ respectively. Cm 3 , which clearly exceeds the atomic number and density of other conventional items. Therefore, a high density and/or a high atomic number region in the detected object can be used as a suspect region, which can greatly reduce the range in which fission detection is performed.
  • X-ray transmission detection and/or neutron transmission detection methods can be utilized when detecting suspect areas.
  • the X-ray beam and the neutron beam used in the X-ray transmission detection and neutron transmission detection methods can use the same X-ray source as the previously performed photo-fission and thermal neutron-induced fission process. This further simplifies the complexity of the entire inspection system.
  • FIG. 1 is an exemplary embodiment of a system for detecting a particular nuclear material of the present invention. detailed description
  • Figure 1 shows a detection system in accordance with a preferred embodiment of the present invention.
  • the system includes an electron accelerator (not shown) that can generate an electron beam 1, which is preferably an electron beam 1 that can emit a plurality of (e.g., two) energies.
  • An electron target 2 is provided in the path of the electron beam 1, which in one embodiment is preferably composed of a base metal.
  • the X-ray beam 3 is generated when the electron beam 1 bombards the electron target 2.
  • the detection system of Figure 1 also includes a photoneutron conversion target 4 that is movable between a working position and an inoperative position.
  • the photoneutron conversion target 4 can be made of heavy water, helium or depleted uranium.
  • the photoneutron conversion target 4 in Fig. 1 is in the operating position, at which time the photoneutron conversion target 4 is in the forward path of the X-ray beam 3.
  • the photoneutron conversion target 4 in Fig. 1 itself also has a beam splitter so that a part of the X-ray beam 3 passes directly through the photoneutron conversion target 4 without any reaction therewith.
  • the beam splitter is in the optical neutron conversion target 4 A passage for a portion of the X-ray beam 3 to pass directly through.
  • the beam splitter With the light neutron conversion target 4, X-rays and photoneutrons can be simultaneously generated.
  • This portion of the X-ray beam 3 that passes directly through the light neutron conversion target 4 is collimated by the X-ray collimator 6 into an X-ray beam 9.
  • Such a light neutron conversion target with a beam splitter as shown in Fig. 1 is described in Chinese Patent Application No. 200810125197.
  • a combination of a photoneutron conversion target and a beam splitter such as the arrangement of the optical neutron conversion target and the beam splitter described in Chinese Patent Application No. 200510086764.
  • These two Chinese patent applications are hereby incorporated by reference.
  • Other independent optical neutron conversion targets and beam splitters are also contemplated.
  • the photoneutron conversion target 4 in Fig. 1 can also be in an inoperative position (not shown), at which time the photoneutron conversion target 4 is outside the forward path of the X-ray beam 3.
  • the X-ray beam 3 can directly illuminate the object 7 to be detected without photoneutron generation.
  • the pivoting structure of the cartridge can be utilized to effect the conversion of the optical neutron conversion target 4 between the working position and the inoperative position.
  • the detection system of Figure 1 also includes an optical neutron collimator 11 for collimating the generated photoneutrons 5 into a photoneutron beam 12.
  • the collimated X-ray beam 9 and the photoneutron beam 12 can enter the object 7 to be detected.
  • the object 7 to be detected may be a vehicle or a container or the like containing a special nuclear material 8 to be detected which may be present.
  • On the other side of the object to be detected there are provided ⁇ / ⁇ ray detectors 10 and neutron detectors 13 spaced apart from each other for detecting ⁇ / emitted from the object 7 during the execution of the detection/ Gamma rays and neutrons.
  • the electron accelerator is adjusted such that it emits an electron beam 1 of a third energy (referred to as a third electron beam in the claims).
  • the light neutron conversion target 4 is moved to its working position.
  • the electron beam 1 bombards the electron target 2 to generate an X-ray beam 3 (referred to as a three-dimensional X-ray beam in the cup claim).
  • the third X-ray beam 3 has a continuous energy spectrum.
  • a portion of the X-ray beam 3 bombards the light neutron conversion target 4, thereby producing a photoneutron beam 5. It should be noted that the optical neutron beam 5 has a continuous energy spectrum.
  • the X neutron collimator 11 collimates the generated photoneutron beam 5 into a photoneutron beam 12. Another portion of the X-ray beam 3 passes through the channel in the photoneutron conversion target 4 and is collimated by the X-ray collimator 6 to form an X-ray beam 9.
  • the X-ray transmission detection is performed on the object 7 by the X-ray beam 9. Specifically, the X-ray beam 9 It enters the object 7 and is attenuated by substances including the special nuclear material 8 that may be present.
  • the X-rays transmitted through the detected object 7 enter the ⁇ / ⁇ ray detector 10.
  • the ⁇ /gamma ray detector 10 detects the incoming X-rays and forms a corresponding electrical signal. The amplitude of the electrical signal reflects the attenuation information of the X-ray beam 9 within the object being detected.
  • the X/ gamma ray detector 10 can be constituted by a one-dimensional detector array arranged along the height direction of the object to be detected.
  • Each measurement of the X/ gamma ray detector 10 can obtain one-dimensional transmission data about a section of the object to be detected.
  • the X-ray beam 9 scans the object 7 to be detected.
  • the two-dimensional transmission data about the X-ray attenuation of the detected object can be obtained by the X-ray detector 10.
  • the two-dimensional transmission data may be utilized to form an X-ray transmission image of the object 7 to be detected.
  • the object neutron beam 12 is used to detect the neutron transmission as described below.
  • the photoneutron beam 12 is incident on the object 7 and is attenuated by substances including the special nuclear material 8 that may be present.
  • the photoneutron beam 12 transmitted through the object 7 is incident on the neutron detector 13.
  • the neutron detector 13 detects the incoming neutrons and forms a corresponding electrical signal.
  • the amplitude of the electrical signal reflects the attenuation information of the optical neutron beam 12 within the object 7 to be detected.
  • the neutron detector 13 can be constituted by a one-dimensional detector array arranged along the height direction of the object to be detected.
  • Each measurement of the neutron detector 13 can obtain one-dimensional transmission data about a section of the object to be inspected. As the object 7 is moved in the direction indicated by the arrow 14, the photoneutron beam 12 scans the object 7 to be detected. Thus, the neutron detector 13 can be used to obtain two-dimensional transmission data of the detected object with respect to neutron attenuation. Alternatively, the two-dimensional transmission data can be utilized to form a neutron transmission image of the object 7 to be detected.
  • the material type information in the object to be detected can be analyzed by a conventional means to determine the region having a high atomic number therein.
  • a conventional means for example, in Chinese Patent Application No. 200510086764. 8
  • an Xx-ray transmission data and neutron transmission data are used to form an nx curve relating only to the equivalent atomic number Z, and the curve is used to identify different materials in the object to be detected. .
  • the present application provides another way to identify material information in a test object.
  • a two-dimensional V-value image The value of V at each pixel (i.e., each detected point in the detected object) in the V-value image is defined as:
  • ⁇ ⁇ ⁇ ) among them, .
  • Indicates the incident neutron beam intensity / modifier indicates the transmitted neutron beam intensity
  • ⁇ ⁇ 0 indicates the incident X-ray beam intensity
  • ⁇ indicates the transmitted X-ray beam intensity.
  • the V value at each pixel is related to the material type at that pixel. When the V value image of the detected object is obtained, the high atomic number region can be determined. The V value image can achieve more sensitive detection of the specific substance in the detected object.
  • High atomic number materials also typically have a high density.
  • two X-ray beams can be used to perform X-ray transmission detection of the detected object in mutually perpendicular directions to determine a high density region therein.
  • the X-ray beam and/or the photoneutron beam generated by the X-ray beam bombardment of the light neutron target is used in determining the suspected region.
  • the entire detection process can be ended, and it is considered that no specific nuclear material is present in the detected object.
  • the photoneutron conversion target 4 is moved to its non-working position.
  • the object 7 is moved by the drag system so that the suspect area is placed at the detection position.
  • the electron accelerator is adjusted such that it emits an electron beam 1 of a first energy (referred to as a first electron beam in the claims).
  • the electron beam 1 bombards the electron target 2 to produce an X-ray beam 3 (referred to as a first X-ray beam in the claims).
  • the energy of the X-ray beam 3 should be such that photo-cracking of a particular nuclear material that may be present in the object 7 to be detected occurs.
  • the electron beam 1 has an energy of not less than 6.5 MeV, for example, between 6.5 MeV and 15 MeV.
  • the first energy can be selected to be 9 MeV.
  • the third energy of the electron beam 1 used in the above detection of the suspect area may be the same as the first energy to reduce the requirement for the electron accelerator.
  • the third energy and the first energy may also be different and may be generated by different electron accelerators.
  • the first X-ray beam 3 is collimated by the collimator 6 into an X-ray beam 9.
  • the suspect area is illuminated with an X-ray beam 9. If a fissile material is present in the suspected area of the test object 7, it will undergo photofission under the irradiation of the X first X-ray beam 3.
  • the product of photofission includes a prompt gamma shot Line and neutron rays and delayed ray and neutron rays (called ⁇ delayed rays).
  • the electron beam 1 is typically an electron beam pulse
  • the X-ray beam 4 is typically a series of X-ray pulses.
  • the gamma ray ray and the neutron ray signal emitted from the object 7 can be measured by the ⁇ / ⁇ ray detector 10 and the neutron detector 13 respectively during the pulse interval of the adjacent X-ray pulses. If the measured intensity of the x-rays and neutron rays exceeds their environmental background level, then the fissile material is present in the suspected area of the test object 7.
  • the ⁇ / ⁇ ray detector 10 and the neutron detector 13 are also used to measure the ⁇ retarded ray. If the measured ⁇ delayed ray exceeds the environmental background level, it is further confirmed that fissile material is indeed present in the detected object.
  • transient or delayed rays may be measured.
  • only gamma rays or neutron rays may be measured.
  • the fissile material is present in the suspected region of the object 7 as long as the measured value of one of the x-ray and neutron rays exceeds its environmental background level.
  • the entire test process can be ended and no special nuclear material is considered to be present in the test object.
  • the photoneutron conversion target 4 is moved back to its working position.
  • the electron accelerator is adjusted to emit a second energy beam 1 (referred to as a second electron beam in the claims). It will be appreciated that in other embodiments, the electron beam 1 having the second energy may also be generated by an additional accelerator.
  • the second electron beam 1 bombards the electron target 2 to produce an X-ray beam 3 (referred to as a second X-ray beam in the claims).
  • the second X-ray beam 3 bombards the light neutron conversion target 4 to produce photoneutrons.
  • the photoneutron is a low-energy neutron whose energy is selected to cause thermal neutron-induced fission of a particular nuclear material that may be present in the fissile material in the test object.
  • the second energy of the electron beam 1 is preferably between 2 MeV and 6 MeV, more preferably between 3 MeV and 5 MeV. In one embodiment, the second energy can be selected to be 4 MeV.
  • the second energy is typically less than the first energy previously described.
  • the energy of the second X-ray beam 3 generated by it does not cause photo fission of the fissile material in the object 7 to be detected, thereby not interfering with the following The process of detecting thermal neutron induced fission.
  • the suspected region of the detected object is irradiated with the generated low-energy neutrons for a certain period of time.
  • the low energy The neutron enters the suspect area after the slowing down. If a special nuclear material is present in the object to be detected 7, low-energy neutrons entering the suspected region cause thermal neutron-induced fission to emit gamma rays and neutron rays.
  • the gamma ray and the neutron ray emitted by the thermal neutron induced fission are measured by the ⁇ / ⁇ ray detector 10 and the neutron detector 13. If the measured neutron and gamma rays exceed the environmental background level, it can be judged that there are special nuclear materials in the suspect area, namely uranium 235 and ⁇ 239.
  • the steps of detecting the suspect area are included in the above embodiment, those skilled in the art will appreciate that in other embodiments, the step may be omitted and the entire object to be detected is used as the detection area to detect the fissile material therein. .
  • the entire object 7 to be inspected can be scanned with the first X-ray beam 3 to determine the position of the fissile material that may be present.

Abstract

A method for inspecting special nuclear material and a system for inspecting special nuclear material using the method are disclosed. The method includes that an object to be inspected (7) is inspected by utilizing both of the irradiation-induced fission characteristic and the thermal neutron induced fission characteristic of the special nuclear material (8). The method further includes that a high-density and/or high atomic number area of the object to be inspected (7) is deemed as a suspicion area to be inspected at first.

Description

一种检测特殊核材料的方法和*** 技术领域  Method and system for detecting special nuclear materials
本发明涉及危险品检测领域， 更具体说， 是涉及一种检测特殊核 材料的方法和***。 技术背景  The present invention relates to the field of dangerous goods detection, and more particularly to a method and system for detecting special nuclear materials. technical background
所谓特殊核材料 ( Specia l Nuc lear Mater ial , 特殊核材料）指 的是能够用来制造核武器的铀和钚， 通常要求铀和钚中含有的铀 235和 钚 239的丰度至少为 93 %。 对于特殊核材料检测来说， 就是检测隐藏在 封装环境（例如车辆或集装箱） 中铀 235和钚 239的存在。 因此， 在下 文中， 所要检测的特殊核材料是指铀 235和钚 239。  The so-called special nuclear material (Specia l Nuc lear Material, special nuclear material) refers to uranium and plutonium that can be used to make nuclear weapons. It is usually required that the uranium and plutonium contained in uranium and plutonium have an abundance of at least 93%. For special nuclear material testing, the presence of uranium 235 and 钚239 hidden in a packaged environment such as a vehicle or container is detected. Therefore, in the following, the special nuclear materials to be tested refer to uranium 235 and 钚239.
已知数公斤至数十公斤量级的特殊核材料即可用于构建简易核 弹， 对社会安全构成极大的威胁。 在某些应用中， 对特殊核材料的检 测限值被定义为 100cm3。与特殊核材料可能所处的封装环境（如集装箱） 相比， 这个体积是非常小的。 另外， 如果***对特殊核材料进行 一定的屏蔽或伪装， 对它的检测难度将会进一步增大。 因此， 如何从 各种口岸流入的货物流中检测出这些并不 "大量" 的特殊核材料， 对 检测技术提出了很大的挑战。 技术。 ' ， 、、 、 _ Λ , , _ Α 、 被动检测技术利用的是特殊核材料的自发衰变现象。 当特殊核材 料的原子核发生自发衰变时， 会放出瞬发中子和 γ射线信号。 利用探 测器对这些射线信号进行收集 /检测， 即可发现特殊核材料。 Special nuclear materials of the order of kilograms to tens of kilograms are known to be used to construct simple nuclear bombs, posing a great threat to social security. In some applications, the detection limit for a particular nuclear material is defined as 100 cm 3 . This volume is very small compared to the packaging environment in which a particular nuclear material may be located, such as a container. In addition, if a terrorist shields or disguise a particular nuclear material, the difficulty of detecting it will be further increased. Therefore, how to detect these special nuclear materials that are not "large" from the flow of goods flowing in various ports poses great challenges to the detection technology. technology. ' , , , , _ Λ , , _ Α , Passive detection technology uses the spontaneous decay of special nuclear materials. When the nucleus of a particular nuclear material spontaneously decays, a prompt neutron and gamma ray signal is emitted. Special nuclear materials can be found by collecting/detecting these ray signals using detectors.
但是， 特殊核材料自发衰变时放出的信号的强度较弱， 因此被动 检测结果会受制于特殊核材料的量及其屏蔽情况， 而且很容易受到屏 蔽的干扰。 如果探测^测量的是信号计数而非能量分布， 则其无法区 分来自特殊核材料的信号与来自自然界的辐射本底（如钾 40的 γ射线、 由宇宙射线产生的中子） ， 因此探测的准确率很低。 而且， 被动检测 技术需要较长时间来收集自发衰变信号， 不适合于需要有较高检测速 度的场合， 诸如机场和港口等口岸。  However, the intensity of the signal emitted by the special nuclear material during spontaneous decay is weak, so the passive detection result is subject to the amount of special nuclear material and its shielding, and is easily interfered by the shielding. If the probe ^ measures the signal count rather than the energy distribution, it cannot distinguish between the signal from the special nuclear material and the radiation background from the natural world (such as the gamma ray of potassium 40, the neutron produced by the cosmic ray), thus detecting The accuracy is very low. Moreover, passive detection techniques take longer to collect spontaneous decay signals and are not suitable for applications where higher detection speeds are required, such as airports and ports.
核共振荧光技术是一种主动检测技术， 其利用特定能量的电磁辐 射来照射特殊核材料。 当该特定能量和特殊核材料的原子核能级一致 的时候， 就会发生强烈的吸收。 通过测量特定能量电磁辐射的吸收情 况， 或者测量物体吸收电磁辐射后发射出 Y光子的能量， 即可对特殊 核材料的存在进行完全确定性的检测。 这是一个准确性很好的方法。 Nuclear resonance fluorescence technology is an active detection technique that utilizes electromagnetic radiation of specific energy. Shoot to illuminate special nuclear materials. When the specific energy and the nuclear energy level of a particular nuclear material are consistent, a strong absorption occurs. By measuring the absorption of specific energy electromagnetic radiation, or measuring the energy of the Y-photon emitted by an object after absorbing electromagnetic radiation, a completely deterministic detection of the presence of a particular nuclear material can be performed. This is a very accurate method.
但是核共振荧光技术需要使用专门的加速器来产生单能的高能 X 射线。 要产生 MeV量级的单能 X射线来照射被检测物， 则需要 l OOMeV以 上的电子加速器和大功率的激光源。 目前， 这种射线源还处于研究阶 段， 不够成熟。 另外一种射线源是直接利用轫致辐射源， 此时对电子 加速器的要求不高， 仅仅要求电子加速到 MeV ~ l OMeV量级， 但是此时 对核共振荧光光子的测量必然伴随有大量的背景干扰， 对测量带来了 很大的干扰， 这是不利的。  However, nuclear resonance fluorescence technology requires the use of specialized accelerators to generate single-energy high-energy X-rays. To generate a single-energy X-ray of the MeV level to illuminate the object to be detected, an electron accelerator of more than OOMeV and a high-power laser source are required. At present, this kind of ray source is still in the research stage and is not mature enough. Another source of radiation is the direct use of the bremsstrahlung source. At this time, the requirements for the electron accelerator are not high. Only electrons are required to accelerate to the MeV ~ l OMeV level. However, the measurement of the nuclear resonance fluorescent photons is inevitably accompanied by a large number of Background interference, which causes a lot of interference with the measurement, is unfavorable.
总之， 前似乎还没有一种行之有效的技术来对特殊核材料（尤 其是隐藏在封装环境中的特殊核材料）进行检测。  In summary, there seems to be no proven technique to detect special nuclear materials, especially special nuclear materials hidden in the packaging environment.
已知， 可裂变材料， 诸如特殊核材料（即， 铀 235和钚 239 ) 以及 其它核材料（例如铀 238和钚 240等）在 射线的照射下会发生光致裂变。 进一步， 特殊核材料在热中子照射下会发生热中子诱发裂变。  It is known that fissile materials, such as special nuclear materials (i.e., uranium 235 and thorium 239) and other nuclear materials (such as uranium 238 and thorium 240), undergo photo-fission under irradiation of radiation. Further, special nuclear materials undergo thermal neutron-induced fission under thermal neutron irradiation.
很显然， 只用光致裂变无法来确定特殊核材料， 因为会受到其它 可裂变材料如铀 238和钚 240等的干扰。光致裂变过程无法区分铀 235和 铀 238 , 也无法区分钚 239和钚 240。  Obviously, only photo-fission can't be used to determine special nuclear materials, because they can be interfered with by other fissile materials such as uranium 238 and thorium 240. The photofission process cannot distinguish between uranium 235 and uranium 238, nor can it distinguish between 钚239 and 钚240.
可以设想仅用热中子诱发裂变来检测特殊核材料。 但是， 热中子 诱发裂变所产生的裂变产物的产额较小， 这降低了对特殊核材料检测 的灵敏度， 容易造成误报警。 如果用热中子长时间照射特殊核材料以 累积足量的裂变信号， 则会造成检测时间过长， 这在对检测速度有要 求的应用场合（例如海关、 港口等） 中是不利的， 而且， 热中子很难 被准直到一狭窄区域。 因此， 即使发现被检测物中存在特殊核材料， 也很难确定其位置。 发明内容  It is conceivable to use only thermal neutrons to induce fission to detect specific nuclear materials. However, the yield of fission products produced by thermal neutron-induced fission is small, which reduces the sensitivity to the detection of special nuclear materials and is prone to false alarms. If a special nucleus material is irradiated by a thermal neutron for a long time to accumulate a sufficient amount of fission signal, the detection time is too long, which is disadvantageous in applications where the detection speed is required (for example, customs, port, etc.), and Thermal neutrons are difficult to be allowed until a narrow area. Therefore, even if a special nuclear material is found in the detected object, it is difficult to determine its position. Summary of the invention
因此， 本发明的目的是提供一种检测特殊核材料的方法和***， 其进行检测。 这种裂变特性是其它原 ΐ核所不具有的， 可以构成对特 殊核材料检测的特征。 按照本发明的一个方面， 提供了一种检测特殊核材料的方法， 包 括： Accordingly, it is an object of the present invention to provide a method and system for detecting a particular nuclear material that is tested. This fission property is not found in other pronuclei nucleus and can constitute a feature for the detection of specific nuclear materials. According to one aspect of the invention, a method of detecting a particular nuclear material is provided, comprising:
用第一 X射线束照射被检测物的检测区域， 该笫一 X射线束的能量 选择为可使被检测物中可能存在的特殊核材料发生可观测的光致裂 变；  Illuminating the detection area of the object with a first X-ray beam, the energy of the X-ray beam being selected to cause observable photodisruption of a particular nuclear material that may be present in the object to be detected;
测量从被检测物发出的由所述光致裂变产生的笫一裂变射线信 号， 如果测量的第一裂变射线信号超过了第一阈值， 则确定被检测物 的检测区域中存在可裂变材料；  Determining a first fission ray signal generated by the photofission from the object to be detected, and if the measured first fission ray signal exceeds a first threshold, determining that a fissile material is present in the detection region of the object to be detected;
当确定存在可裂变材料时， 用低能中子照射被检测物的检测区域， 该低能中子的能量选择为可使被检测物中的所述可裂变材料中的可能 存在的特殊核材料发生热中子诱发裂变；  When it is determined that the fissile material is present, the detection region of the detected object is irradiated with low-energy neutrons, and the energy of the low-energy neutron is selected to cause heat of a special nuclear material which may exist in the fissile material in the object to be detected. Neutron induced fission;
测量从被检测物发出的由所述热中子诱发裂变产生的第二裂变射 线信号， 如果测量的第二裂变射线信号超过了第二阈值， 则确定被检 测物中的所述可裂变材料含有特殊核材料。  Determining, by the detected object, a second fission ray signal generated by the thermal neutron induced fission, and if the measured second fission ray signal exceeds a second threshold, determining that the fissile material in the detected object contains Special nuclear material.
按照本发明的方法， 通过光致裂变过程， 可以利用 X射线束确定被 检测物中是否存在可裂变材料。 进一步， 由于 X射线束具有良好的可准 直性， 按照本发明的方法， 可以在确定存在可裂变材料的同时精确确 定可裂变材料在被检测物中的位置。  According to the method of the present invention, by the photofission process, an X-ray beam can be utilized to determine whether or not a fissile material is present in the object to be detected. Further, since the X-ray beam has good collimability, according to the method of the present invention, the position of the fissile material in the object to be detected can be accurately determined while determining the presence of the fissile material.
由于利用光致裂变检测可裂变材料这一过程可以进行得比较快， 且在被检测物中没有检测到可裂变材料时， 可以不再进行后续的热中 子诱发裂变过程， 因此， 可以大大缩短整个检测过程所用的时间。 这 非常适合于对检测速度有要求的应用场合。  Since the process of detecting fissile material by photodisruption can be carried out relatively quickly, and no fissile material is detected in the detected object, the subsequent thermal neutron-induced fission process can be omitted, and thus can be greatly shortened The time taken for the entire inspection process. This is ideal for applications where inspection speed is required.
可以在确定存在可裂变材料时才进行后续的热中子诱发裂变， 以 确定其中是否存在特殊核材料。 由于已经确定了可裂变材料的存在， 因此， 即使用热中子照射被检测物较短时间， 也不会显著提高误报警 率。 这样， 相比于只用热中子诱发裂变来检测特殊核材料， 本发明的 方法能够提高检测速度以及检测的准确率。  Subsequent thermal neutron induced fission can be performed in determining the presence of fissile material to determine if a particular nuclear material is present. Since the presence of fissile material has been determined, the use of thermal neutrons to illuminate the object for a short period of time does not significantly increase the false alarm rate. Thus, the method of the present invention can improve the detection speed and the accuracy of detection as compared to the detection of a particular nuclear material by thermal fission-induced fission.
在本发明的一个优选实施例中， 所述第一裂变射线信号可以包括 信号。 这样通过在光致裂变过程中检测瞬发裂变射线信号、 并在光致 裂变过程之后检测延迟裂变射线信号， 可以对可裂变材料的存在进行 双重 （重复）确认， 以提高检测的准确性。 在本发明的一个优选实施例中， 所述低能中子可以是用第二 X射线 束轰击光中子转换靶所产生的光中子， 这样就可以用同一个 X射线源 (例如由电子加速器和电子靶构成）来产生第一和第二 X射线束， 以降 低检测***的复杂性和成本。 In a preferred embodiment of the invention, the first fissile ray signal may comprise a signal. Thus, by detecting the prompt fission ray signal during photofission and detecting the delayed fission ray signal after the photofission process, a double (repetitive) confirmation of the presence of the fissile material can be performed to improve the accuracy of the detection. In a preferred embodiment of the present invention, the low-energy neutron may be a light neutron generated by bombarding the light neutron conversion target with the second X-ray beam, so that the same X-ray source can be used (for example, by an electron accelerator) And the electronic target are configured to generate the first and second X-ray beams to reduce the complexity and cost of the detection system.
在本发明的一个优选实施例中， 该方法还包括在用所述第一 X射线 束进行照射之前检测所述被检测物的嫌疑区域， 并且将该嫌疑区域作 为所述检测区域。 已知， 除了上述的裂变特性， 特殊核材料还具有高 密度且高原子序数的特性， 例如铀和鈈的原子序数分别为 92和 94， 密 度分别为 18. 95g/cm3和 19. 84g/cm3,这都明显超过了其它常规物品的原 子序数和密度。 因此， 可以将所述被检测物中的高密度和 /或高原子序 数区域作为嫌疑区域， 这样可以大大降低进行裂变检测的范围。 In a preferred embodiment of the invention, the method further comprises detecting a suspected region of the detected object prior to the irradiating with the first X-ray beam, and using the suspected region as the detection region. It is known that, in addition to the fission characteristics described above, the special nuclear material has a high density and a high atomic number, for example, uranium and thorium have an atomic number of 92 and 94, respectively, and a density of 18.95 g/cm 3 and 19.84 g/ respectively. Cm 3 , which clearly exceeds the atomic number and density of other conventional items. Therefore, a high density and/or a high atomic number region in the detected object can be used as a suspect region, which can greatly reduce the range in which fission detection is performed.
在检测嫌疑区域时， 可以利用 X射线透射检测和 /或中子透射检测 方法。 X射线透射检测和中子透射检测方法中所用的 X射线束和中子束 可以用与之前进行的光致裂变和热中子诱发裂变过程相同的 X射线源。 这进一步简化了整个检测***的复杂性。 附图说明  X-ray transmission detection and/or neutron transmission detection methods can be utilized when detecting suspect areas. The X-ray beam and the neutron beam used in the X-ray transmission detection and neutron transmission detection methods can use the same X-ray source as the previously performed photo-fission and thermal neutron-induced fission process. This further simplifies the complexity of the entire inspection system. DRAWINGS
图 1是本发明的检测特殊核材料的***的一个示例性实施例。 具体实施方式  1 is an exemplary embodiment of a system for detecting a particular nuclear material of the present invention. detailed description
图 1示出了按照本发明的一个优选实施例的检测***。 如图 1所示， 该***包括电子加速器（未示出） ， 该电子加速器可以产生电子束 1， 该电子加速器优选可以发出多种（例如两种）能量的电子束 1。 在电子 束 1的路径中设有电子靶 2， 在一个实施例中， 该电子靶 2优选由钽金属 构成。 当电子束 1轰击该电子靶 2时产生 X射线束 3。  Figure 1 shows a detection system in accordance with a preferred embodiment of the present invention. As shown in Fig. 1, the system includes an electron accelerator (not shown) that can generate an electron beam 1, which is preferably an electron beam 1 that can emit a plurality of (e.g., two) energies. An electron target 2 is provided in the path of the electron beam 1, which in one embodiment is preferably composed of a base metal. The X-ray beam 3 is generated when the electron beam 1 bombards the electron target 2.
图 1中的检测***还包括光中子转换靶 4， 该光中子转换靶 4可在工 作位置和非工作位置之间移动。 该光中子转换靶 4可由重水、 铍或者贫 铀制成。 图 1中的光中子转换靶 4处于工作位置， 此时， 光中子转换靶 4 处于 X射线束 3的前行路径中。 这样， 当 X射线束 3轰击该光中子转换靶 4 时， 就会从光中子转换耙 4中产生光中子 5。 图 1中的光中子转换靶 4自 身还带有分束器， 以便使得 X射线束 3的一部分直接穿过该光中子转换 靶 4而不与其发生任何反应。 具体地， 该分束器是该光中子转换靶 4中 的供 X射线束 3的一部分直接穿过的通道。这样，利用该光中子转换靶 4， 可以同时产生 X射线和光中子。 直接穿过光中子转换靶 4的这一部分 X射 线束 3被 X射线准直器 6准直为 X射线束 9。 The detection system of Figure 1 also includes a photoneutron conversion target 4 that is movable between a working position and an inoperative position. The photoneutron conversion target 4 can be made of heavy water, helium or depleted uranium. The photoneutron conversion target 4 in Fig. 1 is in the operating position, at which time the photoneutron conversion target 4 is in the forward path of the X-ray beam 3. Thus, when the X-ray beam 3 bombards the light neutron conversion target 4, the photoneutron 5 is generated from the photoneutron conversion 耙4. The photoneutron conversion target 4 in Fig. 1 itself also has a beam splitter so that a part of the X-ray beam 3 passes directly through the photoneutron conversion target 4 without any reaction therewith. Specifically, the beam splitter is in the optical neutron conversion target 4 A passage for a portion of the X-ray beam 3 to pass directly through. Thus, with the light neutron conversion target 4, X-rays and photoneutrons can be simultaneously generated. This portion of the X-ray beam 3 that passes directly through the light neutron conversion target 4 is collimated by the X-ray collimator 6 into an X-ray beam 9.
如图 1所示的这样一种带有分束器的光中子转换靶 4记载于在中国 专利申请 200810125197. 6中。 当然， 也可以采用光中子转换靶和分束 器的其它形式的组合，诸如中国专利申请 No. 200510086764. 8中所记载 的光中子转换靶和分束器的布置方式。 这***专利申请在此引入 作为参考。 其它的独立的光中子转换靶和分束器也是可以考虑的。  Such a light neutron conversion target with a beam splitter as shown in Fig. 1 is described in Chinese Patent Application No. 200810125197. Of course, it is also possible to use a combination of a photoneutron conversion target and a beam splitter, such as the arrangement of the optical neutron conversion target and the beam splitter described in Chinese Patent Application No. 200510086764. These two Chinese patent applications are hereby incorporated by reference. Other independent optical neutron conversion targets and beam splitters are also contemplated.
图 1中的光中子转换靶 4还可以处于非工作位置（未示出） ， 此时， 光中子转换靶 4处于 X射线束 3的前行路径之外。 这样， X射线束 3可以直 接照射被检测物 7， 而不会有光中子产生。 可以利用筒单的枢转结构来 实现光中子转换靶 4在工作位置和非工作位置之间的转换。 当光中子转 换靶 4处于非工作位置时， 由 X射线准直器 6将来自电子靶 2的 X射线束 3 准直为 X射线束 9。  The photoneutron conversion target 4 in Fig. 1 can also be in an inoperative position (not shown), at which time the photoneutron conversion target 4 is outside the forward path of the X-ray beam 3. Thus, the X-ray beam 3 can directly illuminate the object 7 to be detected without photoneutron generation. The pivoting structure of the cartridge can be utilized to effect the conversion of the optical neutron conversion target 4 between the working position and the inoperative position. When the photoneutron conversion target 4 is in the inoperative position, the X-ray beam 3 from the electron target 2 is collimated by the X-ray collimator 6 into the X-ray beam 9.
图 1中的检测***还包括光中子准直器 11， 用于将所产生的光中子 5准直为光中子束 12。  The detection system of Figure 1 also includes an optical neutron collimator 11 for collimating the generated photoneutrons 5 into a photoneutron beam 12.
经准直的 X射线束 9和光中子束 12可以进入该被检测物 7。 该被检测 物 7可以是车辆或者集装箱等， 其中含有可能存在的、 待检测的特殊核 材料 8。 在被检测物的另一侧设有相互间隔开的 Χ/ γ射线探测器 10和中 子探测器 13， 用于探测在执行检测过程中从被检测物 7发射和 /或透射 出的 Χ/ γ射线和中子。  The collimated X-ray beam 9 and the photoneutron beam 12 can enter the object 7 to be detected. The object 7 to be detected may be a vehicle or a container or the like containing a special nuclear material 8 to be detected which may be present. On the other side of the object to be detected, there are provided Χ/γ ray detectors 10 and neutron detectors 13 spaced apart from each other for detecting Χ/ emitted from the object 7 during the execution of the detection/ Gamma rays and neutrons.
下面进一步结合图 1来介绍本发明的用于特殊核材料的检测方法。  The detection method for a particular nuclear material of the present invention will be further described below in conjunction with FIG.
1 )检测被检测物中具有高密度和 /或高原子序数的嫌疑区域  1) detecting suspected areas with high density and/or high atomic number in the detected object
调节电子加速器， 使得其发出第三能量的电子束 1 (在权利要求中 称为第三电子束） 。 将光中子转换靶 4移动至其工作位置。 该电子束 1 轰击电子靶 2， 产生 X射线束 3 (在杯利要求中称为笫三 X射线束） 。 需 要注意的是， 该第三 X射线束 3具有连续能谱。  The electron accelerator is adjusted such that it emits an electron beam 1 of a third energy (referred to as a third electron beam in the claims). The light neutron conversion target 4 is moved to its working position. The electron beam 1 bombards the electron target 2 to generate an X-ray beam 3 (referred to as a three-dimensional X-ray beam in the cup claim). It should be noted that the third X-ray beam 3 has a continuous energy spectrum.
一部分 X射线束 3轰击光中子转换靶 4， 从而产生光中子束 5。 需要 注意的是， 该光中子束 5具有连续能谱。 X中子准直器 11将所产生的光 中子束 5准直为光中子束 12。 另一部分 X射线束 3穿过光中子转换靶 4中 的通道， 并经 X射线准直器 6准直后形成 X射线束 9。  A portion of the X-ray beam 3 bombards the light neutron conversion target 4, thereby producing a photoneutron beam 5. It should be noted that the optical neutron beam 5 has a continuous energy spectrum. The X neutron collimator 11 collimates the generated photoneutron beam 5 into a photoneutron beam 12. Another portion of the X-ray beam 3 passes through the channel in the photoneutron conversion target 4 and is collimated by the X-ray collimator 6 to form an X-ray beam 9.
用 X射线束 9对被检测物 7进行 X射线透射检测。 具体地， X射线束 9 进入被检测物 7中， 并被包括可能存在的特殊核材料 8在内的物质所衰 减。 透射出被检测物 7的 X射线进入 Χ/ γ射线探测器 10。 该 Χ/ γ射线探 测器 10探测所进入的 X射线， 并形成对应的电信号。 该电信号的幅度反 映了 X射线束 9在被检测物内的衰减信息。 该 X/ γ射线探测器 10可由沿 着被检测物的高度方向布置的一维探测器阵列构成。 该 X/ γ射线探测 器 10的每一次测量可以得到关于被检测物的一个截面的一维透射数 据。 随着被检测物 7沿着箭头 14所示的方向移动， X射线束 9对被检测物 7进行扫描。 这样， 利用 X射线探测器 10可以获得该被检测物的关于 X射 线衰减的二维透射数据。 可选地， 可利用该二维透射数据形成被检测 物 7的 X射线透射图像。 The X-ray transmission detection is performed on the object 7 by the X-ray beam 9. Specifically, the X-ray beam 9 It enters the object 7 and is attenuated by substances including the special nuclear material 8 that may be present. The X-rays transmitted through the detected object 7 enter the Χ/γ ray detector 10. The Χ/gamma ray detector 10 detects the incoming X-rays and forms a corresponding electrical signal. The amplitude of the electrical signal reflects the attenuation information of the X-ray beam 9 within the object being detected. The X/ gamma ray detector 10 can be constituted by a one-dimensional detector array arranged along the height direction of the object to be detected. Each measurement of the X/ gamma ray detector 10 can obtain one-dimensional transmission data about a section of the object to be detected. As the object 7 is moved in the direction indicated by the arrow 14, the X-ray beam 9 scans the object 7 to be detected. Thus, the two-dimensional transmission data about the X-ray attenuation of the detected object can be obtained by the X-ray detector 10. Alternatively, the two-dimensional transmission data may be utilized to form an X-ray transmission image of the object 7 to be detected.
在利用 X射线束 9对被检测物 7进行 X射线透射检测的同时， 用光中 子束 12对被检测物 7进行如下所述的中子透射检测。 具体地， 该光中子 束 12射入该被检测物 7 , 并被包括可能存在的特殊核材料 8在内的物质 所衰减。 透射出被检测物 7的光中子束 12进入中子探测器 13。 该中子探 测器 13探测所进入的中子， 并形成对应的电信号。 该电信号的幅度反 映了光中子束 12在被检测物 7内的衰减信息。 该中子探测器 13可由沿着 被检测物的高度方向布置的一维探测器阵列构成。 该中子探测器 13的 每一次测量可以得到关于被检测物体的一个截面的一维透射数据。 随 着被检测物 7沿着箭头 14所示的方向移动， 光中子束 12对被检测物 7进 行扫描。 这样， 利用中子探测器 13可以获得该被检测物的关于中子衰 减的二维透射数据。 可选地， 可利用该二维透射数据形成被检测物 7的 中子透射图像。  While the X-ray beam 9 is used to perform X-ray transmission detection on the object 7 to be detected, the object neutron beam 12 is used to detect the neutron transmission as described below. Specifically, the photoneutron beam 12 is incident on the object 7 and is attenuated by substances including the special nuclear material 8 that may be present. The photoneutron beam 12 transmitted through the object 7 is incident on the neutron detector 13. The neutron detector 13 detects the incoming neutrons and forms a corresponding electrical signal. The amplitude of the electrical signal reflects the attenuation information of the optical neutron beam 12 within the object 7 to be detected. The neutron detector 13 can be constituted by a one-dimensional detector array arranged along the height direction of the object to be detected. Each measurement of the neutron detector 13 can obtain one-dimensional transmission data about a section of the object to be inspected. As the object 7 is moved in the direction indicated by the arrow 14, the photoneutron beam 12 scans the object 7 to be detected. Thus, the neutron detector 13 can be used to obtain two-dimensional transmission data of the detected object with respect to neutron attenuation. Alternatively, the two-dimensional transmission data can be utilized to form a neutron transmission image of the object 7 to be detected.
根据上述得到的 X射线透射数据和中子透射数据， 即可利用常规手 段分析被检测物中的材料种类信息， 从而确定其中具有高原子序数的 区域。 例如， 在中国专利 6申请 No. 200510086764. 8中， 利用 X射线透射 数据和中子透射数据构成只和等效原子序数 Z有关的 n-x曲线， 并利用 该曲线来识别被检测物中的不同材料。  According to the X-ray transmission data and the neutron transmission data obtained as described above, the material type information in the object to be detected can be analyzed by a conventional means to determine the region having a high atomic number therein. For example, in Chinese Patent Application No. 200510086764. 8, an Xx-ray transmission data and neutron transmission data are used to form an nx curve relating only to the equivalent atomic number Z, and the curve is used to identify different materials in the object to be detected. .
本申请提供了另一种方式来识别被检测物中的材料信息。 具体地， 的二维 V值图像。 该 V值图像中每个像素点 （即被检测物中的每个被检 测点）处的 V值定义为：  The present application provides another way to identify material information in a test object. Specifically, a two-dimensional V-value image. The value of V at each pixel (i.e., each detected point in the detected object) in the V-value image is defined as:
ν =
Figure imgf000008_0001
ιιχΰ) 其中， 。表示入射中子束强度， /„表示透射中子束强度， ιχ0表示 入射 X射线束强度， ^表示透射 X射线束强度。 每个像素处的 V值 该像 素处的材料种类相关。 这样， 当得到被检测物的 V值图像后， 即可确定 其中的高原子序数区域。 该 V值图像可以实现对被检测物中特异物质的 更灵敏的检测。 ν =
Figure imgf000008_0001
Ιι χΰ ) among them, . Indicates the incident neutron beam intensity, /„ indicates the transmitted neutron beam intensity, ι χ0 indicates the incident X-ray beam intensity, and ^ indicates the transmitted X-ray beam intensity. The V value at each pixel is related to the material type at that pixel. When the V value image of the detected object is obtained, the high atomic number region can be determined. The V value image can achieve more sensitive detection of the specific substance in the detected object.
高原子序数的材料通常也具有高密度。  High atomic number materials also typically have a high density.
在其它实施例中， 也可以采用其它方式来确定被检测物中的嫌疑 区域。 例如， 可以利用两个 X射线束沿相互垂直的方向对被检测物进行 X射线透射检测， 以确定其中的高密度区域。  In other embodiments, other means may be employed to determine the suspected area in the test object. For example, two X-ray beams can be used to perform X-ray transmission detection of the detected object in mutually perpendicular directions to determine a high density region therein.
优选地， 在确定嫌疑区域时使用 X射线束和 /或由 X射线束轰击光中 子靶产生的光中子束。 这有利于与下面将要描述的过程利用同一个 X射 线源 （例如由电子加速器和电子耙构成） ， 以降低***的复杂性和成 本。  Preferably, the X-ray beam and/or the photoneutron beam generated by the X-ray beam bombardment of the light neutron target is used in determining the suspected region. This facilitates the use of the same X-ray source (e.g., consisting of an electron accelerator and an electronic 与) with the process to be described below to reduce system complexity and cost.
如果在该步骤中没有在被检测物中发现高密度和 /或高原子序数 的区域， 则可结束整个检测过程， 并认为被检测物中不存在特殊核材 料。  If a region of high density and/or high atomic number is not found in the detected object in this step, the entire detection process can be ended, and it is considered that no specific nuclear material is present in the detected object.
2 )在嫌疑区域中探测可裂变材料 2) Detection of fissile material in suspect areas
在发现有嫌疑区域之后， 将光中子转换靶 4移动到其非工作位置。 利用拖动***移动该被检测物 7， 使得该嫌疑区域被置于检测位置上。  After the suspected area is found, the photoneutron conversion target 4 is moved to its non-working position. The object 7 is moved by the drag system so that the suspect area is placed at the detection position.
调节电子加速器， 使得其发出笫一能量的电子束 1 (在权利要求中 称为第一电子束） 。 该电子束 1轰击电子靶 2， 产生 X射线束 3 (在权利 要求中称为第一 X射线束）。 该 X射线束 3的能量应该能够使得被检测物 7中可能存在的特殊核材料发生光致裂变。 为此， 电子束 1所具有的笫 一能量最好不低于 6. 5Mev， 例如在 6. 5Mev和 15Mev之间。 在一个实施例 中， 该第一能量可选择为 9Mev。  The electron accelerator is adjusted such that it emits an electron beam 1 of a first energy (referred to as a first electron beam in the claims). The electron beam 1 bombards the electron target 2 to produce an X-ray beam 3 (referred to as a first X-ray beam in the claims). The energy of the X-ray beam 3 should be such that photo-cracking of a particular nuclear material that may be present in the object 7 to be detected occurs. For this reason, the electron beam 1 has an energy of not less than 6.5 MeV, for example, between 6.5 MeV and 15 MeV. In one embodiment, the first energy can be selected to be 9 MeV.
需要注意的是， 在上述的检测嫌疑区域时所用的电子束 1所具有的 第三能量可以与该第一能量相同， 以降低对电子加速器的要求。 当然， 第三能量与第一能量也可以不同， 而且可以由不同的电子加速器产生。  It should be noted that the third energy of the electron beam 1 used in the above detection of the suspect area may be the same as the first energy to reduce the requirement for the electron accelerator. Of course, the third energy and the first energy may also be different and may be generated by different electron accelerators.
第一 X射线束 3经准直器 6准直为 X射线束 9。 用 X射线束 9照射该嫌疑 区域。 如果在被检测物 7的嫌疑区域中存在可裂变材料， 其在 X第一 X射 线束 3的照射下将会发生光致裂变。 该光致裂变的产物包括瞬发的 γ射 线和中子射线和延迟的 Y射线和中子射线（称为 Ρ延迟射线） 。 The first X-ray beam 3 is collimated by the collimator 6 into an X-ray beam 9. The suspect area is illuminated with an X-ray beam 9. If a fissile material is present in the suspected area of the test object 7, it will undergo photofission under the irradiation of the X first X-ray beam 3. The product of photofission includes a prompt gamma shot Line and neutron rays and delayed ray and neutron rays (called Ρ delayed rays).
由于电子束 1通常为电子束脉冲， 因此， X射线束 4通常为一系列 X 射线脉冲。 这样， 可以在相邻 X射线脉冲的脉冲间隔期间， 利用 Χ/ γ射 线探测器 10和中子探测器 13分别测量从被检测物 7中发出的瞬发 γ射 线和中子射线信号。 如果测量到的 Υ射线和中子射线的强度超过了它 们的环境本底水平， 则说明被检测物 7的该嫌疑区域中存在可裂变材 料。  Since the electron beam 1 is typically an electron beam pulse, the X-ray beam 4 is typically a series of X-ray pulses. Thus, the gamma ray ray and the neutron ray signal emitted from the object 7 can be measured by the Χ/γ ray detector 10 and the neutron detector 13 respectively during the pulse interval of the adjacent X-ray pulses. If the measured intensity of the x-rays and neutron rays exceeds their environmental background level, then the fissile material is present in the suspected area of the test object 7.
优选是， 在停止 X射线束 3的照射之后， 还利用 Χ/ γ射线探测器 10 和中子探测器 13测量 Ρ延迟射线。 如果所测量的 Ρ延迟射线超出了环 境本底水平， 则进一步确认了被检测物中确实存在可裂变材料。  Preferably, after the irradiation of the X-ray beam 3 is stopped, the Ρ/γ ray detector 10 and the neutron detector 13 are also used to measure the Ρ retarded ray. If the measured Ρ delayed ray exceeds the environmental background level, it is further confirmed that fissile material is indeed present in the detected object.
在其它一些实施例中， 也可只测量瞬发射线或延迟射线。 在另一 些实施例中， 也可以只测 γ射线或中子射线。 在又一些实施例中， 只 要 Υ射线和中子射线中的一种的测量值超出其环境本底水平， 则说明 被检测物 7的该嫌疑区域中存在可裂变材料。  In other embodiments, only transient or delayed rays may be measured. In other embodiments, only gamma rays or neutron rays may be measured. In still other embodiments, the fissile material is present in the suspected region of the object 7 as long as the measured value of one of the x-ray and neutron rays exceeds its environmental background level.
如果在该步骤中没有在嫌疑区域中可裂变材料， 则可结束整个检 测过程， 并认为被检测物中不存在特殊核材料。  If there is no fissile material in the suspect area in this step, the entire test process can be ended and no special nuclear material is considered to be present in the test object.
3 )探测特殊核材料 3) Detection of special nuclear materials
在发现存在可裂变材料之后， 将光中子转换靶 4移回到其工作位 置。 调节电子加速器， 使其发出笫二能量的电子束 1 (在权利要求中称 为笫二电子束） 。 可以理解， 在其它实施例中， 也可以由另外的加速 器来产生该具有第二能量的电子束 1。  After the discovery of the fissile material, the photoneutron conversion target 4 is moved back to its working position. The electron accelerator is adjusted to emit a second energy beam 1 (referred to as a second electron beam in the claims). It will be appreciated that in other embodiments, the electron beam 1 having the second energy may also be generated by an additional accelerator.
该第二电子束 1轰击电子靶 2 , 产生 X射线束 3 (在权利要求中称为 第二 X射线束） 。 第二 X射线束 3轰击光中子转换靶 4， 产生光中子。 该 光中子为低能中子， 其能量选择为可使被检测物中的可裂变材料中的 可能存在的特殊核材料发生热中子诱发裂变。 为此， 电子束 1所具有的 第二能量最好在 2Mev与 6Mev之间， 更优选在 3Mev与 5Mev之间。 在一个 实施例中， 该第二能量可选择为 4Mev。 该第二能量通常小于前述的第 一能量。 对于具有所选第二能量的电子束 1来说， 其所产生的第二 X射 线束 3的能量不会使得被检测物 7中的可裂变材料发生光致裂变， 从而 不会干扰下述的关于热中子诱发裂变的检测过程。  The second electron beam 1 bombards the electron target 2 to produce an X-ray beam 3 (referred to as a second X-ray beam in the claims). The second X-ray beam 3 bombards the light neutron conversion target 4 to produce photoneutrons. The photoneutron is a low-energy neutron whose energy is selected to cause thermal neutron-induced fission of a particular nuclear material that may be present in the fissile material in the test object. For this reason, the second energy of the electron beam 1 is preferably between 2 MeV and 6 MeV, more preferably between 3 MeV and 5 MeV. In one embodiment, the second energy can be selected to be 4 MeV. The second energy is typically less than the first energy previously described. For the electron beam 1 having the selected second energy, the energy of the second X-ray beam 3 generated by it does not cause photo fission of the fissile material in the object 7 to be detected, thereby not interfering with the following The process of detecting thermal neutron induced fission.
用所产生的低能中子照射被检测物的嫌疑区域一定时间。 该低能 中子在慢化之后进入嫌疑区域。 如果在被检测物 7中存在特殊核材料， 进入嫌疑区域的低能中子使其发生热中子诱发裂变， 从而发出 γ射线 和中子射线。 The suspected region of the detected object is irradiated with the generated low-energy neutrons for a certain period of time. The low energy The neutron enters the suspect area after the slowing down. If a special nuclear material is present in the object to be detected 7, low-energy neutrons entering the suspected region cause thermal neutron-induced fission to emit gamma rays and neutron rays.
在停止第二 X射线束 3或者低能中子的照射后， 利用 Χ/ γ射线探测 器 10和中子探测器 13测量由于热中子诱发裂变而发出的 γ射线和中子 射线。 如果所测得的中子射线和 γ射线超过了环境本底水平， 则可以 判断该嫌疑区域存在特殊核材料， 即铀 235和钚 239。 尽管在上述实施例中包括检测嫌疑区域的步驟， 但是本领域技术 人员可以理解， 在其它一些实施例中， 也可以省略该步骤， 并且将整 个被检测物作为检测区域来检测其中的可裂变材料。 在这种情况下， 可以用第一 X射线束 3对整个被检测物 7进行扫描， 从而确定可能存在的 可裂变材料的位置。 虽然根据本发明的多个实施例介绍了本发明， 但是应当理解， 这 些实施例是示例性的而非限定性。 本领域技术人员在所附权利要求的 范围内， 可以对这些实施例进行各种变化。  After stopping the irradiation of the second X-ray beam 3 or low-energy neutrons, the gamma ray and the neutron ray emitted by the thermal neutron induced fission are measured by the Χ/γ ray detector 10 and the neutron detector 13. If the measured neutron and gamma rays exceed the environmental background level, it can be judged that there are special nuclear materials in the suspect area, namely uranium 235 and 钚239. Although the steps of detecting the suspect area are included in the above embodiment, those skilled in the art will appreciate that in other embodiments, the step may be omitted and the entire object to be detected is used as the detection area to detect the fissile material therein. . In this case, the entire object 7 to be inspected can be scanned with the first X-ray beam 3 to determine the position of the fissile material that may be present. While the invention has been described in terms of various embodiments of the invention, it is understood that Various changes to these embodiments can be made by those skilled in the art within the scope of the appended claims.

Claims

权 利 要 求 Rights request
1. 一种检测特殊核材料的方法， 包括： 1. A method of detecting special nuclear materials, including:
用第一 X射线束照射被检测物的检测区域， 该笫一 X射线束的能量 选择为可使被检测物中可能存在的特殊核材料发生可观测的光致裂 变；  Illuminating the detection area of the object with a first X-ray beam, the energy of the X-ray beam being selected to cause observable photodisruption of a particular nuclear material that may be present in the object to be detected;
测量从被检测物发出的由所述光致裂变产生的第一裂变射线信 号， 如果测量的第一裂变射线信号超过了第一阈值， 则确定被检测物 的检测区域中存在可裂变材料；  Determining, by the object to be detected, a first fissile ray signal generated by the photofission, if the measured first fission ray signal exceeds a first threshold, determining that a fissile material is present in the detection region of the object to be detected;
用低能中子照射被检测物的检测区域， 该低能中子的能量选择为 可使被检测物中的所述可裂变材料中的可能存在的特殊核材料发生热 中子诱发裂变；  Irradiating the detection region of the detected object with low energy neutrons, the energy of the low energy neutron being selected to cause thermal neutron induced fission of a special nuclear material which may be present in the fissile material in the object to be detected;
测量从被检测物发出的由所述热中子诱发裂变产生的第二裂变射 线信号， 如果测量的第二裂变射线信号超过了笫二阈值， 则确定被检 测物中的所述可裂变材料含有特殊核材料。  Determining, by the detected object, a second fission ray signal generated by the thermal neutron induced fission, and if the measured second fission ray signal exceeds a second threshold, determining that the fissile material is contained in the object to be detected Special nuclear material.
2.根据权利要求 1所述的方法，其中，所述第一裂变射线信号包括： 从被检测物发出的瞬发裂变射线信号和 /或延迟裂变射线信号。  2. The method of claim 1 wherein the first fission ray signal comprises: a prompt fission ray signal and/or a delayed fission ray signal emanating from the object being detected.
3. 根据权利要求 2所述的方法， 其中， 所述笫一 X射线束包括一系 列 X射线脉冲， 对所述瞬发裂变射线信号的测量是在所述第一 X射线束 的相邻脉冲之间的脉冲间隔期间进行的。  3. The method according to claim 2, wherein the first X-ray beam comprises a series of X-ray pulses, and the measurement of the prompt fission ray signal is an adjacent pulse of the first X-ray beam Performed during the pulse interval between.
4. 根据权利要求 2所述的方法， 其中， 对所述延迟裂变射线信号 的测量是在停止所述第一 X射线束之后进行的。  4. The method of claim 2, wherein the measuring of the delayed fission ray signal is performed after stopping the first X-ray beam.
5. 根据权利要求 2所述的方法， 其中， 对所述第一裂变射线信号 的测量包括既测量瞬发裂变射线信号还测量所述延迟裂变射线信号， 以便对所述可裂变材料的存在进行双重确认。  5. The method of claim 2, wherein measuring the first fissile ray signal comprises measuring both a prompt fission ray signal and a measured delayed fissure ray signal to effect presence of the fissile material Double confirmation.
6. 根据权利要求 1所述的方法， 其中， 所述低能中子包括用第二 X 射线束轰击光中子转换靶所产生的光中子。  6. The method of claim 1, wherein the low energy neutrons comprise bombarding the light neutrons produced by the light neutron conversion target with a second X-ray beam.
7.根据权利要求 6所述的方法， 其中， 所述笫二 X射线束的能量选 择成低于使得所述可裂变材料发生可观测的光致裂变的能量。  7. The method of claim 6, wherein the energy of the xenon X-ray beam is selected to be lower than the energy that causes observable photofission of the fissile material.
8.根据权利要 6所述的方法， 其中， 对第二裂变射线信号的测量是 在停止所述第二 X射线束之后进行的。  The method according to claim 6, wherein the measuring of the second fission ray signal is performed after the stopping of the second X-ray beam.
9.根据权利要求 6所述的方法， 其中， 所述第一和第二 X射线束分 别是用不同能量的第一和第二电子束轰击电子靶来产生的， 并且， 第 一电子束的能量高于第二电子束的能量。 The method according to claim 6, wherein the first and second X-ray beams are divided It is produced by bombarding the electron target with the first and second electron beams of different energies, and the energy of the first electron beam is higher than the energy of the second electron beam.
10. 根据权利要求 9所述的方法， 其中， 所述笫一电子束的能量选 择为不低于 6. 5Mev。  10. The method according to claim 9, wherein the energy of the first electron beam is selected to be not less than 6.5 MeV.
11. 根据权利要求 10所述的方法， 其中， 所述第一电子束的能量 选择为在 6. 5Mev和 15Mev之间。  11. The method of claim 10, wherein the energy of the first electron beam is selected to be between 6.5 MeV and 15 MeV.
12.根据权利要求 9所述的方法， 其中， 所述第二电子束的能量在 2Mev与 6Mev之间。  The method according to claim 9, wherein the energy of the second electron beam is between 2 MeV and 6 MeV.
13.根据权利要求 12所述的方法， 其中， 所述第二电子束的能量在 3Mev与 5Mev之间。  The method according to claim 12, wherein the energy of the second electron beam is between 3 MeV and 5 MeV.
14.根据权利要求 9所述的方法， 其中， 所述第一和第二电子束由 同一电子加速器来产生。  14. The method of claim 9, wherein the first and second electron beams are generated by a same electron accelerator.
15.根据权利要求 1所述的方法， 其中， 所述第一和第二裂变射线 信号分别包括 Y射线和 /或中子射线信号。  The method of claim 1, wherein the first and second fissile ray signals respectively comprise Y-rays and/or neutron-ray signals.
16. 根据权利要求 15所述的方法， 其中， 所述笫一和 /或笫二阈值 选择为 Y射线和 /或中子射线的环境本底。  16. The method according to claim 15, wherein the first and/or second threshold is selected as an environmental background of Y-rays and/or neutron rays.
17.根据权利要求 1所述的方法， 还包括：  17. The method of claim 1 further comprising:
在用所述笫一 X射线束进行照射之前， 检测所述被检测物的嫌疑区 域， 并且将该嫌疑区域作为所述检测区域； 并且  Detecting a suspected region of the detected object, and using the suspected region as the detection region, before irradiating with the x-ray beam; and
所述嫌疑区域包括所述被检测物中的高密度和 /或高原子序数区 域。  The suspected area includes a high density and/or high atomic number area in the detected object.
18.根据权利要求 17所述的方法， 其中， 检测所述高原子序数区域 包括：  18. The method of claim 17, wherein detecting the high atomic number region comprises:
对所述被检测物进行 X射线透射检测和中子透射检测， 并用所获得 的 X射线透射数据和中子透射数据来确定被检测物中的高原子序数区 域。  X-ray transmission detection and neutron transmission detection are performed on the object to be detected, and the obtained X-ray transmission data and neutron transmission data are used to determine a high atomic number region in the object to be detected.
19. 根据权利要求 18所述的方法， 其中， 所述 X射线透射检测使用 连续能谱 X射线束， 所述中子透射检测使用连续能谱中子束， 所述 X射 , 被检测物的 V值图像中的每个像素处的 V值定义为：  19. The method according to claim 18, wherein the X-ray transmission detection uses a continuous energy spectrum X-ray beam, and the neutron transmission detection uses a continuous energy spectrum neutron beam, the X-ray, the object to be detected The V value at each pixel in the V value image is defined as:
^ = 1η(/„//„0)/1η(/χ //χ0) ^ = 1η(/„//„ 0 )/1η(/ χ // χ0 )
其中， /η。表示入射中子束强度， /„表示透射中子束强度， Jx0表示 入射 X射线束强度， /^表示透射 X射线束强度， 每个像素处的 V值与该像 素处的材料种类相关。 Where /η . Indicates the incident neutron beam intensity, /„ denotes the transmitted neutron beam intensity, J x0 denotes The intensity of the incident X-ray beam, /^ indicates the intensity of the transmitted X-ray beam, and the value of V at each pixel is related to the type of material at that pixel.
20.根据权利要求 19所述的方法， 其中， 所述连续能谱 X射线束由 第三 X射线束的一部分形成， 所述连续能谱中子束由所述笫三 X射线束 的另一部分轰击光中子靶形成。  20. The method of claim 19, wherein the continuous energy spectrum X-ray beam is formed by a portion of a third energy beam, the continuous energy spectrum neutron beam being another portion of the third X-ray beam The bombardment of light neutron targets is formed.
21.根据权利要求 20所述的方法， 其中，  The method according to claim 20, wherein
所述第三 X射线束与所述笫一 X射线束分别是用笫三和第一电子束 轰击电子靶来产生。  The third X-ray beam and the X-ray beam are respectively generated by bombarding the electron target with a third electron beam and a first electron beam.
22.根据权利要求 21所述的方法， 其中，  22. The method of claim 21, wherein
所述第三和第一电子束具有相同的能量。  The third and first electron beams have the same energy.
23.根据权利要求 21所述的方法， 其中，  23. The method of claim 21, wherein
所述第三和第二电子束由同一电子加速器产生。  The third and second electron beams are generated by the same electron accelerator.
24.—种检测特殊核材料的***， 包括：  24. A system for detecting special nuclear materials, including:
电子束源， 其用于分别产生笫一、 笫二和第三电子束；  An electron beam source for respectively generating a first, a second, and a third electron beam;
电子靶， 其定位成使得所述第一、 第二和第三电子束轰击所述电 子靶， 从而分别产生第一、 第二和第三 X射线束；  An electron target positioned such that the first, second, and third electron beams bombard the electronic target to generate first, second, and third X-ray beams, respectively;
分束器；  Beam splitter
光中子转换靶， 其可在工作位置和非工作位置之间移动；  a light neutron conversion target that is movable between a working position and a non-working position;
X/ Y射线探测器和中子探测器， 用于探测从被检测物中发出和 /或 透射出的 X/ Y射线和中子射线信号；  An X/Y ray detector and a neutron detector for detecting X/Y ray and neutron ray signals emitted and/or transmitted from the object to be detected;
其中， 当所述电子加速器发出第三电子束时， 所述光中子转换靶 处于工作位置， 所述分束器从所述第三 X射线束分出第一部分和笫二部 分， 所述第一部分轰击光中子转换靶， 从而产生光中子束； 所述 X射线 束的第二部分以及所述光中子束分别用于对被检测物进行 X射线透射 检测和中子透射检测；  Wherein, when the electron accelerator emits a third electron beam, the light neutron conversion target is in an operating position, and the beam splitter separates the first portion and the second portion from the third X-ray beam, the Part of the bombardment light neutron conversion target, thereby generating a light neutron beam; the second portion of the X-ray beam and the light neutron beam are respectively used for X-ray transmission detection and neutron transmission detection of the detected object;
其中， 当所述电子加速器发出笫一电子束时， 所述光中子转换靶 处于非工作位置， 所述第一电子束的能量设置成使得所述第一 X射线束 能够使被检测物中可能存在的特殊核材料发生光致裂变；  Wherein, when the electron accelerator emits a first electron beam, the light neutron conversion target is in an inoperative position, and the energy of the first electron beam is set such that the first X-ray beam enables an object to be detected Photo-fission occurs in special nuclear materials that may be present;
其中， 当所述电子加速器发出第二电子束时， 所述光中子转换靶 处于工作位置， 所述第二 X射线束轰击所述光中子转换靶产生低能中 子， 所述第二电子束的能量设置成使得所述低能中子能够使被检测物 中可能存在的特殊核材料发生热中子诱发裂变。 Wherein, when the electron accelerator emits a second electron beam, the light neutron conversion target is in an operating position, and the second X-ray beam bombards the light neutron conversion target to generate low energy neutrons, the second electron The energy of the beam is set such that the low energy neutrons are capable of causing thermal neutron induced fission of a particular nuclear material that may be present in the analyte.
25.根据权利要求 24所述的***， 其中， 所述电子束源包括单个电 子加速器， 用于产生所述笫一、 第二和第三电子束。 25. The system of claim 24, wherein the electron beam source comprises a single electron accelerator for generating the first, second and third electron beams.
26.根据权利要求 25所述的***， 其中， 所述电子加速器产生的笫 一和第三电子束具有相同的第一较高能量， 所述第二电子束具有第二 较低能量。  26. The system of claim 25, wherein the first and third electron beams produced by the electron accelerator have the same first higher energy and the second electron beam has a second lower energy.
27. 根据权利要求 24所述的***， 其中， 所述光中子转换靶借助 一枢传机构而在所述工作位置与所述非工作位置之间移动。  27. The system of claim 24, wherein the optical neutron conversion target is moved between the working position and the inoperative position by a pivot mechanism.
28.根据权利要求 27所述的***， 其中， 所述分束器是在所述光中 子转换靶中形成的通道。  28. The system of claim 27, wherein the beam splitter is a channel formed in the photoneutron conversion target.
29.根据权利要求 24所述的***， 其中， 所述电子靶由钽制成。 29. The system of claim 24, wherein the electronic target is made of tantalum.
30.根据权利要求 24所述的***，其中，所述光中子转换靶由重水、 铍或者贫铀制成。 30. The system of claim 24, wherein the photoneutron conversion target is made of heavy water, helium or depleted uranium.
31.根据权利要求 24所述的***， 其中， 所述电子束源构造成按照 第三、 笫一和第二的顺序发射所述电子束。  31. The system of claim 24, wherein the electron beam source is configured to emit the electron beam in a third, first, and second order.
32.根据权利要求 31所述的***， 其中， 第三电子束用于检测所述 被检测物中的高密度和 /或高原子序数区域。  The system according to claim 31, wherein the third electron beam is for detecting a high density and/or high atomic number region in the object to be detected.
33. 根据权利要求 24所述的方法， 其中， 所述第一电子束的能量 选择为不低于 6. 5Mev。  33. The method according to claim 24, wherein the energy of the first electron beam is selected to be not less than 6.5 MeV.
34. 根据权利要求 33所述的方法， 其中， 所述第一电子束的能量 选择为在 6. 5Mev和 15Mev之间。  34. The method of claim 33, wherein the energy of the first electron beam is selected to be between 6.5 MeV and 15 MeV.
35.根据权利要求 24所述的方法， 其中， 所述第二电子束的能量在 2Mev与 6Mev之间。  35. The method of claim 24, wherein the energy of the second electron beam is between 2 MeV and 6 MeV.
36.根据权利要求 35所述的方法， 其中， 所述第二电子束的能量在 3Mev与 5Mev之间。  36. The method of claim 35, wherein the energy of the second electron beam is between 3 MeV and 5 MeV.
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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2490636B (en) * 2010-02-25 2017-02-08 Rapiscan Systems Inc Systems and methods for detecting nuclear material
US9625606B2 (en) 2009-05-16 2017-04-18 Rapiscan Systems, Inc. Systems and methods for high-Z threat alarm resolution
US10393915B2 (en) 2010-02-25 2019-08-27 Rapiscan Systems, Inc. Integrated primary and special nuclear material alarm resolution

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2933498B1 (en) * 2008-07-04 2012-07-06 Smiths Heimann Sas METHOD AND DEVICE FOR DETECTING THE PRESENCE, IN A LOAD, OF SUSPICIOUS OBJECTS CONSISTING OF HIGH ATOMIC WEIGHT NUCLEAR MATERIALS
JP5630666B2 (en) * 2012-03-30 2014-11-26 住友重機械工業株式会社 Neutron capture therapy collimator and neutron capture therapy device
CN104754852B (en) * 2013-12-27 2019-11-29 清华大学 Nuclide identification method, nuclide identifier system and photoneutron transmitter
FR3016969B1 (en) * 2014-01-24 2017-05-05 Commissariat Energie Atomique DEVICE FOR MEASURING BERYLLIUM QUANTITY IN A RADIOACTIVE OBJECT
JP6742259B2 (en) * 2017-03-02 2020-08-19 住友重機械工業株式会社 Neutron beam detection system and method for setting neutron beam detection system
BR112019025088B1 (en) * 2017-05-31 2023-12-19 Aachen Institute For Nuclear Training Gmbh METHOD AND DEVICE FOR THE ANALYSIS OF MULTIPLE ELEMENTS BASED ON NEUTRON ACTIVATION AND USE
US10705243B2 (en) 2018-01-29 2020-07-07 Korea Atomic Energy Research Institute Nondestructive inspection system
US11061164B1 (en) * 2019-06-06 2021-07-13 National Technology & Engineering Solutions Of Sandia, Llc System, algorithm, and method using short pulse interrogation with neutrons to detect and identify matter
CN114324430B (en) * 2022-03-07 2022-06-17 合肥金星智控科技股份有限公司 Detection device based on neutron activation
CN114942468A (en) * 2022-05-23 2022-08-26 西北核技术研究所 Method and device for non-contact rapid detection of special nuclear materials

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02114160A (en) * 1988-10-25 1990-04-26 Nippon Atom Ind Group Co Ltd Nuclear substance analyzer
CN1196797A (en) * 1995-09-18 1998-10-21 麦托雷克国际公司 Method and apparatus for detecting and identifying fissionable material
US7277521B2 (en) * 2003-04-08 2007-10-02 The Regents Of The University Of California Detecting special nuclear materials in containers using high-energy gamma rays emitted by fission products
US7359480B2 (en) * 2004-04-23 2008-04-15 Lawrence Livermore National Security, Llc Neutron interrogation system using high gamma ray signature to detect contraband special nuclear materials in cargo

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4497768A (en) * 1982-07-07 1985-02-05 The United States Of America As Represented By The United States Department Of Energy Apparatus and method for quantitatively evaluating total fissile and total fertile nuclide content in samples
WO1992003722A1 (en) * 1990-08-15 1992-03-05 Massachusetts Institute Of Technology Detection of explosives and other materials using resonance fluorescence, resonance absorption, and other electromagnetic processes with bremsstrahlung radiation
US5838759A (en) * 1996-07-03 1998-11-17 Advanced Research And Applications Corporation Single beam photoneutron probe and X-ray imaging system for contraband detection and identification
CN100582758C (en) * 2005-11-03 2010-01-20 清华大学 Method and apparatus for recognizing materials by using fast neutrons and continuous energy spectrum X rays
US8718219B2 (en) * 2007-06-14 2014-05-06 Passport Systems, Inc. Non-intrusive method to identify presence of nuclear materials using energetic prompt neutrons from photon-induced fission
DE112008001662T5 (en) 2007-06-21 2010-05-20 Tsinghua University Method and system for the detection of contraband using photoneutrons and x-rays
US7622709B2 (en) * 2007-09-12 2009-11-24 Hamilton Sundstrand Corporation Variable-ratio neutron-gamma ray source

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02114160A (en) * 1988-10-25 1990-04-26 Nippon Atom Ind Group Co Ltd Nuclear substance analyzer
CN1196797A (en) * 1995-09-18 1998-10-21 麦托雷克国际公司 Method and apparatus for detecting and identifying fissionable material
US7277521B2 (en) * 2003-04-08 2007-10-02 The Regents Of The University Of California Detecting special nuclear materials in containers using high-energy gamma rays emitted by fission products
US7359480B2 (en) * 2004-04-23 2008-04-15 Lawrence Livermore National Security, Llc Neutron interrogation system using high gamma ray signature to detect contraband special nuclear materials in cargo

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9625606B2 (en) 2009-05-16 2017-04-18 Rapiscan Systems, Inc. Systems and methods for high-Z threat alarm resolution
GB2490636B (en) * 2010-02-25 2017-02-08 Rapiscan Systems Inc Systems and methods for detecting nuclear material
EP2539902A4 (en) * 2010-02-25 2018-01-10 Rapiscan Systems, Inc. Systems and methods for detecting nuclear material
US10393915B2 (en) 2010-02-25 2019-08-27 Rapiscan Systems, Inc. Integrated primary and special nuclear material alarm resolution

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